Tone keying and synthesizing system for electronic musical instrument

ABSTRACT

First and second latching selectors receive tone signals from the tone generators and are operatively coupled to a keyboard for respectively deriving first and second tone signals having frequencies determined by the depressed keys in the keyboard. The frequencies of the first and the second tone signals are respectively divided by first and second frequency dividers respectively having predetermined dividing factors of, for example, 2 and 3, so that the first and the second frequency divided tone signals (i.e., the signals at the outputs of the frequency dividers) have a frequency ratio which is close to but not exactly equal to an integer. The mixed resultant tone exhibits an ensemble effect as produced by a multi-series tone generator.

United States Patent 1191 Adachi TONE KEYING AND SYNTHESIZING SYSTEM FORELECTRONIC MUSICAL INSTRUMENT [75] Inventor: Takeshi Adachi, Hamamatsu,Japan [73] Assignee: Nippon Gakki Seizo Kabushiki Kaisha,I-lamamatsu-shi,

Shizuoka-ken, Japan [22] Filed: Dec. 6, 1972 [21] App]. No.: 312,680

[30] Foreign Application Priority Data Dec. 29, 1971 Japan 47-2142 Feb.10, 1972 Japan..... Feb. 10, 1972 Japan 47-14688 [52] US. Cl 84/l.01,84/1.22, 84/1.24, 84/DIG. 4 [51] Int. Cl. G10h 1/02, G10h 5/06 [58]Field of Search ..84/1.01,1.03,1.11-1.13, 84/1.19-1.26, DIG. 11, DIG. 2,DIG. 4

[56] References Cited UNITED STATES PATENTS 3,509,262 4/1970 Munch84/1.01 3,499,090 3/1970 Meyer 84/1.0l 3,509,454 4/1970 Gossel 84/l.0l X3,215,767 11/1965 Martin 84/1.24

R F! 13 f f fiiiii fiiii 1 LATCHING SELECTOR I U 83 u 11 $1 F Fi i F F FF F Ti F LATCHING SELECTOR 51 Feb. 5, 1974 Primary Examiner-Stephen J.Tomsky Assistant Examiner--Stanley J. Witkowski Attorney, Agent, orFirm-Flynn & Frishauf [5 7] ABSTRACT First and second latching selectorsreceive tone signals from the tone generators and are operativelycoupled to a keyboard for respectively deriving first and second tonesignals having frequencies determined by the depressed keys in thekeyboard. The frequencies of the first and the second tone signals arerespectively divided by first and second frequency dividers respectivelyhaving predetermined dividing factors of, for example, 2 and 3, so thatthe first and the second frequency divided tone signals (i.e., thesignals at the outputs of the frequency dividers) have a frequency ratiowhich is close to but not exactly equal to an integer. The mixedresultant tone exhibits an ensemble effect as produced by a multi-seriestone generator.

23 Claims, 8 Drawing Figures OUTPUT 2' 3 PEDAL KEYBOARD PAIENTEDFEB 519M3.790.693

KEYBOARD OUTPUT TONE KEYING AND SYNTHESIZING SYSTEM FOR ELECTRONICMUSICAL INSTRUMENT This invention relates to a tone keying andsynthesizing system for an electronic musical instrument and moreparticularly to a tone keying and synthesizing system capable ofrendering tones which are artificially produced by electronic musicalinstruments truthful to those obtained from natural musical instruments.

Tones derived from natural musical instruments have the followingfeatures. First, the fundamental waves and harmonics are not lockedtogether in phase and in frequency. Secondly, the harmonic componentsproduce humming sounds. Thirdly, when tones begin to be generated, or atthe rise of tones, there appear relatively fast attenuating harmoniccomponents whose frequencies do not represent an integral multiple ofthat of the fundamental waves. Therefore, at the starting moments orrises of the tones, they have unstable pitch frequencies.

The prior art electronic musical instrument will now be discussed inconnection with the above-mentioned first feature of tones obtained fromnatural musical instruments. In a conventional electronic musicalinstrument, output signals from the master oscillators have theirfrequency successively divided by two to produce a plurality of octavelyrelated tone signals. Therefore, the mixed fundamental and harmonic tonesignals are unavoidably locked in phase. To resolve this drawback, someof the prior art elecronic musical instruments mix fundamental tonesignals having the frequency divided by two with harmonic tone signalshaving the frequency divided by an odd number. For example, a tonesignal corresponding to note C2 (65.406 Hz) has a frequency to provide,when divided by two, a signal denoting a fundamental wave of note Cl(32.703 B2). A tone signal corresponding to note G3 195.998 Hz) has afrequency to produce, when divided by three, a signal having a frequencyof 65.333 Hz (a second harmonic wave of note Cl). Both the fundamentalwave and the harmonic component thus obtained are mixed in an attempt toattain truthfulness to the tones of natural musical instruments.According to such approach, however, formation of a tone signalrepresenting note C1 requires tone signals or tone generators denotingnotes C2 and G3 separated more than one octave from each other,resulting in a complicated circuit arrangement of tone generators.

The aforesaid second feature of tones obtained from natural musicalinstruments can not be simulated simply by mixing octavely related tonesignals.

Further to simulate the third feature of natural musical instruments,some of the conventional electronic musical instruments cause thefrequency of a tone signal to be shifted during the short period inwhich a key is depressed. This process can indeed vary the frequency ofthe rising portion of a sustained tone, but fails to attain truthfulnessto the tones of natural musical instruments due to the absence of afundamental wave in the rising portion of the tone being produced.

It is accordingly the object of this invention to provide an electronicmusical instrument capable of producing tones truthful to those ofnatural musical instruments by a simple circuit arrangement of tonekeying and synthesizing circuits.

SUMMARY OF THE INVENTION An electronic musical instrument according tothis invention is provided with at least first and second latchingselectors operatively coupled with keys in a keyboard and having inputterminals normally supplied with tone signals and deriving upon keydepression first and second tone signals having frequencies determinedby the depressed key. The first and the second tone signals have theirfrequencies divided by first and second frequency dividers havingfrequency dividing factors of first and second predetermined numbers,either of which does not constitute a power of a number 2 (i.e., 2 2 2with respect to the other. Outputs from the frequency dividers are mixedby a mixer.

Since "the first" and the second frequency dividers carry out frequencydivision by the numbers, either of which does not represent a power of 2with respect to the other, output signals from the frequency dividersare not in exact integer relationship. Where the output of the firstfrequency divider should constitute a fundamental wave and that of thesecond frequency divider a harmonic component thereof, it is onlyrequired that the frequency of the output of either of these twofrequency dividers be a substantially integral multiple (at least 2) ofthe frequency of the other. If the outputs of the first and secondfrequency dividers are purposely made to have frequenciesbearing a ratioof substantially 1, then the fundamental waves or harmonic componentswill be accompanied with humming as is observed in the tones of naturalmusical instruments.

Further, between the first frequency divider and the input terminal ofthe mixer is provided a first gate for supplying a first tone signalwith a sustained envelope. Between the second frequency divider and themixer input terminal is positioned a second gate for supplying a secondtone signal with a decaying envelope. Accordingly, when tones begin tobe generated, they have unstable pitch frequencies.

' The present invention can be more fully understood from the followingdetailed description when taken in connection with the accompanyingdrawings, in which:

FIG. 1 is a block diagram of a tone keying and synthesizing system foran electronic musical instrument according to a first embodiment of thisinvention;

FIG. 2 is a schematic illustration for better understanding of theoperation of the system of FIG. 1;

FIG. 3 is a block diagram of a tone keying and synthesizing systemaccording to a second embodiment of the invention;

FIG. 4 is a modification of FIG. 3;

7 FIG. 5 is a block diagram of a tone keying and synthesizing systemaccording to a third embodiment of the invention;

FIGS. 6A and 63 present the envelope forms of tone signals produced bythe tone keying and synthesizing system of FIG. 5; and

FIGS. 7 and 8 are block diagrams, in combination, of a tone keying andsynthesizing system according to still another embodiment of theinvention.

FIG. 1 is a block diagram of a tone keying and synthesizing systemaccording to a first embodiment of this invention, showing the manner inwhich there are mixed a fundamental wave and its harmonic component.Reference numberals 11 and 12 represent the known first and secondlatching selectors. These latching selectors l1 and 12 are connected toreceive tone signals of notes C4 to C5 and those of notes G3 to G4respectively. The latching selectors 11 and 12 are further operativelycoupled to a pedal keyboard 13 having keys representing notes C2 to C3,thereby producing upon key depression first and second tone signalsbearing a predetermined frequency relationship. The latching selectors11 and 12 are respectively so designed as to derive a single tone signaleven when there are simultaneously depressed a plurality of keys of thepedal keyboard 13.

Where there is depressed a key 21 of the pedal keyboard 13 correspondingto, for example, note A2, the first latching selector l1 draws out afirst tone signal representing note A4, and the second latching selectorl2 draws out a second tone signal denoting note E4. These first andsecond tone signals are supplied to amplifiers 14 and 15 and then to afirst frequency divider 16 having a division ratio of 2 and a secondfrequency divider 17 having a division ratio of 3, so as to be subjectedto frequency division to become an A3 signal and an approximate A2signal respectively. After the frequency division, the first and secondtone signals are conducted to first and second gate circuits 18 and 19later to be mixed together in a mixer 20. The first and second gatecircuits 18 and 19, which may be of a known type, are operativelycoupled to the pedal keyboard 13 to permit the passage of tone signalsonly upon key depression. Details and correlations of the latchingselectors, the keyboard and gates are of such known construction as isdisclosed in the US. Pat. No. 3,598,892 to Yamashita.

There will now be described the operation of the tone keying andsynthesizing system of FIG. 1. When there is depressed the key 21 of thepedal keyboard 13 corresponding to note A2, there are derived, asdescribed above, a first tone signal representing note A4 (440 Hz) and asecond tone signal denoting note E4 (329.63 Hz). As shown in FIG. 2, thefirst tone signal has its frequency divided into a signal having afrequency of 220 Hz by the first frequency divider l6 and the secondtone signal into a signal having a frequency of 109.88 Hz by the secondfrequency divider 17. An output from the second frequency divider 17corresponds to the fundamental wave of the tone signal representing noteA2 and an output from the first frequency divider 16 represents thesecond harmonic wave of the tone signal corresponding to note A2. Fromthe output terminal of the mixer are obtained a fundamental wave and asecond harmonic wave having a frequency close to but not exactly twiceof the fundamental frequency, thereby producing a tone approximatelytruthful to that of a natural musical instrument. To obtain a tonesignal corresponding to note A2, there are required tone generatorsassociated with notes A4 and E4 included in the range of one octave,thus simplifying the circuit arrangement of tone generators.

Where the tone keying and synthesizing system of FIG. 1 is employed as apedal keyboard playing section in an electronic organ including a manualkeyboard playing section of a conventional frequency dividing tonegenerator system, the organ can produce a good ensemble effect, becausethe fundamental wave of the pedal tone is obtained by a frequencydivision by an odd number (3 in FIG. 1) whereas the fundamental waves ofthe manual tones are obtained by a frequency signal representing note Cl(32.70 Hz), t h ere rHay be used any of the following processes:

Process 1 C4(261.64 Hz) monic of C1 G3(196.00 Hz) monic of C1 E3( 164.81Hz) wave of Cl paieessz C5(523.25 Hz) monic of Cl G4(392.00 Hz) monic ofC1 B4 (329.63 Hz) monic of C1 D4 (293.67 Hz) g waveo f Cd Process 3C4(261.63 Hz) monic of cl D4(293.67 Hz) of Cl E4(329.63 Hz) monic of ClD4(293.67 Hz) wave of Cl As mentioned above, to produce a tone signal,it is advised that the frequency division ratio for the funda- :-2130.81 Hz fourth har- +3 65.33 Hz second har- +5 32.96 Hz fundamental261.63 Hz eighth har- 130.67 Hz fourth har- 65.93 Hz second har- +2130.81 HZ fourth har- 3 97.89 Hz third harmonic +5 65.93 Hz second har-+9 32.63 Hz fundamental mental wave is the largest and odd number usedin the frequency division of each process which does not constitute apower of 2 with respect to a frequency division ratio for a harmoniccomponent.

FIG. 3 is a block diagram of a tone keying and synthesizing systemaccording to a second embodiment of this invention which is intended tointroduce a bumming effect into the tones generated thereby. The partsof FIG. 3 the same as those of FIG. 1 are denoted by the same numerals.The first latching selector 11 is supplied with tone signalscorresponding to notes C3 to C4 (130.81 Hz to 261.63 Hz), and the secondlatching selector 12 with tone signals representing notes E4 to E5(329.63 Hz to 659.26 Hz) which respectively have a pitch one octave andmajor third higher than notes C3 to C4. A second frequency divider 17effects frequency division by 5. A gate circuit 21 is connected to theoutput side of the mixer 20.

The first tone signal derived from the latching selector 11 has itsfrequency divided by the first frequency divider 16 into a frequencywithin 65.40 to 130.81 Hz, and the second tone signal derived from thelatching selector 12 has its frequency divided by the second frequencydivider 17 into 65.92 to 131.85 Hz. Therefore, between the dividedfrequency of the first tone signal and that of the second tone signal,there is a difference of 13.6 cents, namely, there arises a hummingsound having a beat frequency of 0.52 to 1.04 Hz. Thus the intermediatefrequency region of a bass tone contains a humming sound having afrequency of about 1 Hz.

If the second latching selector 12 were supplied with tone signalscorresponding to notes G3 to G4 (196.00 Hz to 392.00 Hz) and the secondfrequency divider 17 32.63 Hz fundamentfi effects frequency division by3, then the divided frequencies of the first and second tone signalswould have a difference of only 2 cents. Thus the frequency differencewould be reduced to only about 0.2 Hz at the middle of the output octaveregion. Such'a small frequency difference would produce no significanteffect particularly for a quick performance.

If the second frequency divider 17 carries out frequency division byseven or nine, then the divided frequencies of the first and second tonesignals would have a difference of 65 or 4 cents. A difference of 65cents is too large, while adiffefence of 4 centsis too small. Therefore,the second frequency divider 17 is most preferred to effect frequencydivision by five.

Referring to FIG. 3, the second tone signal has its frequency divided byfive. However, the frequency divided output wave does not have a 50percent duty factor, giving rise to an unsatisfactory tone color. Thisdrawback can be eliminated by supplying the second latching selector l2,as shown in FIG. 4, with tone signals representing the notes E5 to E6which respectively have a pitch one octave higher than thosecorresponding to the notes E4 to E5 as are employed in FIG. 3, andfurther connecting a third frequency divider 22 effecting frequencydivision by 2 to the output side of the second frequency divider 17.

FIG. 5 is a block diagram of a tone keying and synthesizing systemaccording to a third embodiment of thisinvention which is capable ofcausing tone signals to have unstable pitch frequencies when they beginto be generated. The parts of FIG. 5 the same as those of FIG. 1 aredenoted by the same numerals. As in FIG. 3, the first latching selector11 is supplied with tone signals corresponding to notes C3 to C4, andthe second latching selector 12 with tone signals representing notes E4to E5. The second frequency divider l7 effects frequency division by 5.A first gate circuit 18 supplies an output from the first frequencydivider 16 with a sustained envelope indicated in FIG. 6A. A second gatecircuit 19 supplies an output from the second frequency divider 17 witha percussive envelope as shown in FIG. 6B. These gate circuits have aknown arrangement, such as those shown in US. Pat. No. 3,571,481 toAdachi, and description thereof is omitted.

As long as the output from the second frequency divider 17 has afrequency bearing a ratio of approximagely one to that of the firstfrequency divider 16, the second frequency divider 17 may carry outfrequency division by three or seven in place of five. The tone keyingand synthesizing system of FIG.- 5 causes tone signals to have unstablepitch frequencies during the extremely short period at the startingmoment of the tone sounding in spite of the presence of a fundamentalpitch and thereafter causes the tone signals to have a sustained stablepitch frequency, thereby producing tones truthful to those of naturalmusical instruments.

- from the divider chains tone signals representing notes C3 to C4,notes G4 to G5, notes E5 to E6 and notes D6 to D7 respectively. Outputsfrom the first to fourth latching selectors 38 to 41 are supplied tofirst to fourth frequency dividers 43 to 46 respectively. Thesefrequency dividers effect frequency division by two, three, five andnine respectively. An output from the first frequency divider 43 isconducted to a first divider chain 47 comprised of frequency dividers 48and 49 carrying out frequency division by two. An output from the secondfrequency divider 44 is supplied to a second divider chain 50 comprisedof frequency dividers 51, 52 and S3 effecting frequency division by two.An output from the third frequency divider 45 is supplied to a thirddivider chain 54 comprised of frequency dividers 55, 56, and 57 carryingout frequency division by two. An output from the fourth frequencydivider 46 is conducted to a fourth divider chain 58 comprised offrequency dividers 59, 60 and 61 carrying out frequency division by two.An output 08 from the first frequency divider 43, an output 08 from thefirst unit 51 of the second divider chain 50, an output 08 from thefirst unit 55 of the third divider chain 54 and output 08" from thefirst unit 59 of the fourth divider chain 58 have approximately and notexactly the same frequency. Similarly, outputs 016, 016', 016" and 016"from the frequency dividers 48, 52, 56 and 60 have approximately and notexactly the same frequency. Outputs 032, 032, 032" and 032" also haveapproximately and not exactly the same frequency. As shown in FIG. 8,the outputs 08, 016 and 032 obtained through frequency division by the+two divider 43, the outputs 08, 016 and 032 obtained via frequencydivision by the +three divider 44, the outputs 08", 016" and 032"obtained via frequency division by the 2-five divider 45, and theoutputs 08", 016" and 032" obtained via frequency division by the +ninedivider 46 are supplied to gate circuitries 71 to 74. The first tofourth gate circuitries 71 to 74 are operatively coupled to the pedalkeyboard 42, and each include three gate circuits. Outputs from theindividual gate circuits are fed to twelve manually operable switches S1to S12. The outputs 08, 08', 08 and 08" are mixed via the switches S1,S4, S7 and S10 and in turn applied to first tone coloring filters 75.The outputs 016, 016, 016" and 016' are mixed via the switches S2, S5,S8 and S11 and in turn supplied to second tone coloring filters 76. Theoutputs 032, 032', 032" and 032' are mixed via the switches S3, S6, S9and S12 and in turn supplied to third tone coloring filters 77. Theabovementioned switches S1 to S12 are selectively closed as desired by aplayer, enabling the fundamental or harmonic tone signals to producehumming sounds. The player can selectively close the switches S1 throughS12 singly or in combination at his choice to provide desired toneeffects to meet the respective music requirements.

What is claimed is: 1. An electronic musical instrument comprising: aplurality of tone generators; keyboard means having a plurality of keys;at least first and second latching selectors operatively coupled to saidkeyboard means, said first and second latching selectors each including:input terminals connected to said plurality of tone generators, a singleoutput terminal, and means coupled to said single output terminal forproducing upon key depression respective first and second single tonesignals bearing a predetermined frequency relationship to each other,irrespective of the number of keys which are depressed;

a first frequency divider connected to the output terminal of said firstlatching selector for dividing the frequency of said first tone signalby a first predetermined number to generate a frequency divided firstsignal;

a second frequency divider connected to the output terminal of saidsecond latching selector for dividing the frequency of said second tonesignal by a second predetermined number to generate a frequency dividedsecond signal, said second predetermined number being larger than saidfirst predetermined number but not a power of a number 2 with respect tosaid first predetermined number; and

means coupled to the outputs of said first and second frequency dividersfor mixing said frequency divided first and second tone signals.

2. An electronic musical instrument according to claim 1 wherein saidfrequency divided signal has a frequency bearing a ratio of asubstantially integral number of at least two to that ofsaid frequencydivided second signal.

3. An electronic musical instrument according to claim 1 wherein saidfrequency divided first signal has a frequency bearing a ratio ofsubstantially one to that ofsaid frequency divided second signal.

4. An electronic musical instrument according to claim 3 wherein saidfirst predetermined number is two and said second predetermined numberis an odd number larger than two. I

5. An electronic musical instrument according to claim 4 wherein saidodd number is three.

6. An electronic musical instrument according to claim 4 wherein saidodd number is five.

7. An electronic musical instrument according to claim 2 wherein saidfirst predetermined number is two and said second predetermined numberis an odd number larger than two, and said frequency divided first tonesignal has a frequency representing an approximately and not exactlyintegral multiple of that of said frequency divided second signal.

8. An electronic musical instrument according to claim 7 wherein saidodd number is three.

9. An electronic musical instrument according to claim 1 furthercomprising first and second gate means respectively coupled between saidmixer and said first frequency divider and between said mixer and saidsecond frequency divider, said first and second gate means beingoperatively coupled to said keyboard means.

10. An electronic musical instrument according to claim 9 wherein saidfirst gate means provides a sustained envelope to an output from saidfirst frequency divider, and said second gate means provides apercussive envelope to an output from said second frequency divider.

11. An electronic musical instrument according to claim 10 wherein theoutput signal from said first frequency divider has a frequency bearinga ratio of substantially one relative to the frequency of the outputsignal from said second frequency divider, said first and secondfrequency dividers respectively effecting frequency division by two andfive.

12. An electronic musical instrument according to claim 1 furthercomprising a gate means coupled to the output of said mixer means andoperatively coupled with said keyboard means.

13. An electronic musical instrument according to claim 1 wherein thesecond predetermined number associated with said second frequencydivider is an odd number larger than two, and there is further provideda third frequency divider cascade connected to the output of said secondfrequency divider for dividing the frequency of a signal by an evennumber.

14. An electronic musical instrument according to claim 13 wherein saideven number is two.

15. An electronic musical instrument according to claim 1 wherein saidkeyboard means comprises a pedal keyboard.

16. An electronic musical instrument according to claim 1 wherein thefirst predetermined number associated with said first frequency divideris two, and the second predetermined number associated with said secondfrequency divider is an odd number larger than two, and which furtherincludes a first chain of frequency dividers cascade connected to theoutput of said first frequency divider, the respective frequencydividers of said first chain effecting frequency division by two; asecond chain of frequency dividers cascade connected to the output ofsaid second frequency divider, the respective frequency dividers of saidsecond chain effecting frequency division by two; and a plurality ofmanually operable switches for selectively coupling the outputs of saidfirst frequency divider and the respective frequency dividers of saidfirst and second chains said mixer means.

17. An electronic musical instrument according to claim 16 wherein anoutput from said first frequency divider has a frequency bearing a ratioof substantially one relative to the frequency of the output signal fromthe first frequency divider of said second chain of frequency dividers,said first frequency divider of said second chain of frequency dividersbeing connected to the output of said second frequency divider.

18. An electronic musical instrument according to claim 1 wherein saidfirst predetermined number associated with said first frequency divideris two and said second predetermined number associated with said secondfrequency divider is a first odd number larger than two, and furthercomprising at least third and fourth latching selectors operativelycoupled with said keyboard means; a first chain of frequency dividerscascade connected to the output of said first frequency divider, therespective frequency dividers of said first chain effecting frequencydivision by two; a second chain of frequency dividers cascade connectedto the output of said second frequency divider, the respective frequencydividers of said second chain effecting frequency division by two; athird frequency divider connected to the output of said third latchingselector for effecting frequency division by a second odd number largerthan said first odd number; a third chain of frequency dividers cascadeconnected to the output of said third frequency divider, the respectivefrequency dividers of said third chain effecting frequency division bytwo; a fourth frequency divider connected to the output of said fourthlatching selector for carrying out frequency division by a third oddnumber larger than said second odd number; a fourth chain of frequencydividers cascade connected to the output of said fourth frequencydivider, the respective frequency dividers of said fourth chaineffecting frequency division by two;

20. An electronic musical instrument according to claim 18 wherein saidfirst, second, and third odd numbers are three, five and nine,respectively.

21. An electronic musical instrument according to claim 18 furthercomprising gate means connected between the output of the respectivefrequency dividers of said first to fourth chains and said pluralswitches, said gate means being operatively coupled with said keyboardmeans for supplying outputs from the frequency dividers to thecorresponding switches.

22. An electronic musical instrument according to claim 7 wherein saidodd number is five.

23. An electronic musical instrument according to claim 7 wherein saidodd number is nine.

UNITED STATES PATENT OFFICE I CERTIFICATE OF CORRECTION Patent No.3,790,693 Dated February 5, 1974 Inventor(s) Takeshi ADACHI It iscertified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

On initial Qp'age of patent under the heading of Foreign ApplicationPriority Data add the followin June 21,4972 Japan. 73332/72--;

Column 7, line 22, after "divided insert -first--;

Column 8, line 31, after "chains" insert to--;

Column 8, line 45, after "comprising" insert Signed and sealed this 9thday of July 1974.

(SEAL) Attest:

MCCOY M. GIBSON, JR. I C. MARSHALL DANN Attesting Officer Commissionerof Patents I FORM PO-IOSO (10-69) v 5Com. 6 U.5. GOVIINMINT PRINTINGOFFICE I... D-3l-3SL Patent No. 3 ,790,'693 Dated February 5 1974Inventor(s) Takeshi ADACHI It is certified that error appears in theaboveidentified patent and that said Letters Patent are hereby correctedas shown below:

On initial page of patent under the heading of Foreign ApplicationPriority Data add the following:

-June 21, 1972 Japan. 73332/72--;

Column 7, line 22, after "divided" insert first;

Column 8, line 31 after "chains" insert -to-;

Column 8, line 45, after "comprising" insert Signed and sealed this 9thday of July 1974.

(SEAL) Attest 1 v McCOY M. GIBSON, JR. I C. MARSHALL DANN AttestinszOfficer Commissioner of Patents FORM PO-105O (10-69) USCOMWDC 6037*",

i U. 5. GOVERNMENT PR NTING OFFICE 2 "I, O-BlG-JS.

1. An electronic musical instrument comprising: a plurality of tonegenerators; keyboard means having a plurality of keys; at least firstand second latching selectors operatively coupled to said keyboardmeans, said first and second latching selectors each including: inputterminals connected to said plurality of tone generators, a singleoutput terminal, and means coupled to said single output terminal forproducing upon key depression respective first and second single tonesignals bearing a predetermined frequency relationship to each other,irrespective of the number of keys which are depressed; a firstfrequency divider connected to the output terminal of said firstlatching selector for dividing the frequency of said first tone signalby a first predetermined number to generate a frequency divided firstsignal; a second frequency divider connected to the output terminal ofsaid second latching selector for dividing the frequency of said secondtone signal by a second predetermined number to generate a frequencydivided second signal, said second predetermined number being largerthan said first predetermined number but not a power of a number 2 withrespect to said first predetermined number; and means coupled to theoutputs of said first and second frequency dividers for mixing saidfrequency divided first and second tone signals.
 2. An electronicmusical instrument according to claim 1 wherein said frequency dividedsignal has a frequency bearing a ratio of a substantially integralnumber of at least two to that of said frequency divided second signal.3. An electronic musical instrument according to claim 1 wherein saidfrequency divided first signal has a frequency bearing a ratio ofsubstantially one to that of said frequency divided second signal.
 4. Anelectronic musical instrument according to claim 3 wherein said firstpredetermined number is two and said second predetermined number is anodd number larger tHan two.
 5. An electronic musical instrumentaccording to claim 4 wherein said odd number is three.
 6. An electronicmusical instrument according to claim 4 wherein said odd number is five.7. An electronic musical instrument according to claim 2 wherein saidfirst predetermined number is two and said second predetermined numberis an odd number larger than two, and said frequency divided first tonesignal has a frequency representing an approximately and not exactlyintegral multiple of that of said frequency divided second signal.
 8. Anelectronic musical instrument according to claim 7 wherein said oddnumber is three.
 9. An electronic musical instrument according to claim1 further comprising first and second gate means respectively coupledbetween said mixer and said first frequency divider and between saidmixer and said second frequency divider, said first and second gatemeans being operatively coupled to said keyboard means.
 10. Anelectronic musical instrument according to claim 9 wherein said firstgate means provides a sustained envelope to an output from said firstfrequency divider, and said second gate means provides a percussiveenvelope to an output from said second frequency divider.
 11. Anelectronic musical instrument according to claim 10 wherein the outputsignal from said first frequency divider has a frequency bearing a ratioof substantially one relative to the frequency of the output signal fromsaid second frequency divider, said first and second frequency dividersrespectively effecting frequency division by two and five.
 12. Anelectronic musical instrument according to claim 1 further comprising agate means coupled to the output of said mixer means and operativelycoupled with said keyboard means.
 13. An electronic musical instrumentaccording to claim 1 wherein the second predetermined number associatedwith said second frequency divider is an odd number larger than two, andthere is further provided a third frequency divider cascade connected tothe output of said second frequency divider for dividing the frequencyof a signal by an even number.
 14. An electronic musical instrumentaccording to claim 13 wherein said even number is two.
 15. An electronicmusical instrument according to claim 1 wherein said keyboard meanscomprises a pedal keyboard.
 16. An electronic musical instrumentaccording to claim 1 wherein the first predetermined number associatedwith said first frequency divider is two, and the second predeterminednumber associated with said second frequency divider is an odd numberlarger than two, and which further includes a first chain of frequencydividers cascade connected to the output of said first frequencydivider, the respective frequency dividers of said first chain effectingfrequency division by two; a second chain of frequency dividers cascadeconnected to the output of said second frequency divider, the respectivefrequency dividers of said second chain effecting frequency division bytwo; and a plurality of manually operable switches for selectivelycoupling the outputs of said first frequency divider and the respectivefrequency dividers of said first and second chains said mixer means. 17.An electronic musical instrument according to claim 16 wherein an outputfrom said first frequency divider has a frequency bearing a ratio ofsubstantially one relative to the frequency of the output signal fromthe first frequency divider of said second chain of frequency dividers,said first frequency divider of said second chain of frequency dividersbeing connected to the output of said second frequency divider.
 18. Anelectronic musical instrument according to claim 1 wherein said firstpredetermined number associated with said first frequency divider is twoand said second predetermined number associated with said secondfrequency divider is a first odd number larger than two, and furthercomprising at least third and fourth latching selectors operativelycoupled with said keyboard means; A first chain of frequency dividerscascade connected to the output of said first frequency divider, therespective frequency dividers of said first chain effecting frequencydivision by two; a second chain of frequency dividers cascade connectedto the output of said second frequency divider, the respective frequencydividers of said second chain effecting frequency division by two; athird frequency divider connected to the output of said third latchingselector for effecting frequency division by a second odd number largerthan said first odd number; a third chain of frequency dividers cascadeconnected to the output of said third frequency divider, the respectivefrequency dividers of said third chain effecting frequency division bytwo; a fourth frequency divider connected to the output of said fourthlatching selector for carrying out frequency division by a third oddnumber larger than said second odd number; a fourth chain of frequencydividers cascade connected to the output of said fourth frequencydivider, the respective frequency dividers of said fourth chaineffecting frequency division by two; and a plurality of manuallyoperable switches for selectively coupling to said mixer means theoutputs of said first frequency divider, and the respective frequencydividers constituting said first, second, third and fourth chains. 19.An electronic musical instrument according to claim 18 wherein an outputfrom said first frequency divider, an output from the first frequencydivider of said second chain, an output from the first frequency dividerof said third chain and an output from the first frequency divider ofsaid fourth chain have frequencies which mutually have ratios ofsubstantially one-to-one.
 20. An electronic musical instrument accordingto claim 18 wherein said first, second, and third odd numbers are three,five and nine, respectively.
 21. An electronic musical instrumentaccording to claim 18 further comprising gate means connected betweenthe output of the respective frequency dividers of said first to fourthchains and said plural switches, said gate means being operativelycoupled with said keyboard means for supplying outputs from thefrequency dividers to the corresponding switches.
 22. An electronicmusical instrument according to claim 7 wherein said odd number is five.23. An electronic musical instrument according to claim 7 wherein saidodd number is nine.